Fully covered self-expandable metallic stents with anchor fins: a rose with many thorns

We read with interest the study by Phillips et al. [1]. The authors describe their experience with the use of fully covered self-expandable metallic stents (FCSEMS), with anchor fins as an anti-migration system, for the treatment of biliary leaks after liver transplantation.

In this series of 17 patients, eight (47 %) developed common bile duct (CBD) strictures, and three developed biliary ulcerations following FCSEMS removal. Six of the eight patients with stenosis (35 %) required repeat endoscopic treatment for a clinically significant stricture, whereas in two (12 %) the strictures were not clinically significant and were managed conservatively. The first criticism is that the radiological imaging alone, without clinical signs, is not enough for a diagnosis of biliary stenosis.

One of the six patients was treated with plastic stent placement because of continuous leak after FCSEMS removal; 3 months later this patient developed clinically significant biliary stenosis, though it is doubtful that the stenosis was due to FCSEMS placement. Of the remaining three patients with anastomotic strictures, two received the diagnosis of stenosis before FCSEMS placement. We believe that in these two cases FCSEMS placement as a first approach should probably be considered a failure rather than stenosis being a complication of the placement. Only in one case was the anastomotic stricture diagnosed after FCSEMS removal. Only in the remaining two cases with non-anastomotic stenosis at the proximal CBD could the stenosis be due to anchor fin decubitus. Finally, three patients (18 %) had biliary ulcerations after stent removal. This complication is reported only with this type of FCSEMS, and so appears to be clearly attributable to the anchor fins.

In a study by our group, we evaluated the efficacy and safety of FCSEMS in biliary complications after liver transplantation [2]. In this preliminary study, 11 patients had biliary stenosis, and five had biliary leakage plus stenosis. We had an 87.5 % success rate and no complications other than stent migration in six patients, with no clinical consequences. We have expanded this preliminary study to include a greater number of patients [3]. A total of 54 consecutive patients with biliary stricture and/or leak were treated with FCSEMS placement (Niti-S ComVi fully covered biliary stent, Taewoong Medical, Korea). In this series, no complications related to FCSEMS were observed except for stent migration (33.3 % and 46.7 % in the two groups, respectively). We observed success rates of 71.8 % in patients in whom FCSEMS was placed after failure of conventional endoscopic treatment and 53.3 % in patients treated with FCSEMS as a first approach.

In a study by García-Pajares [4], FCSEMS were placed in 22 patients with stenosis and/or leak. Complications associated with FCSEMS removal (41 %) included duodenal migration in four patients, obstruction in three, proximal biliary migration in one, and FCSEMS embedding into the bile duct in one. FCSEMS placement successfully remodeled the stricture in 21 of 22 patients (95.5 %). Bile leakage disappeared in all patients.

In conclusion, FCSEMS can be recommended for the management of biliary leaks following liver transplantation at this point, but we believe that this should be restricted to FCSEMS with no traumatic anti-migration system. The use of a stent with anchoring fins should be more carefully assessed in light of complications observed.

References

• 1 Phillips M S, Bonatti H, Sauer B G et al. Elevated stricture rate following the use of fully covered self-expandable metal biliary stents for biliary leaks following liver transplantation.  Endoscopy. 2011;  43 512-517
• 2 Traina M, Tarantino I, Barresi L et al. Efficacy and safety of fully covered self-expandable metallic stents in biliary complications after liver transplantation: a preliminary study.  Liver Transpl. 2009;  15 1493-1498
• 3 Tarantino I, Traina M, Barresi L et al. Fully covered self-expandable metallic stents in biliary complications after liver transplantation: efficacy and safety in a large cohort of treated patients.  Gastrointest Endosc. 2011;  73(4 Suppl 1) 115
• 4 García-Pajares F, Sánchez-Antolín G, Pelayo S L et al. Covered metal stents for the treatment of biliary complications after orthotopic liver transplantation.  Transplant Proc. 2010;  42 2966-2969

1 M. Traina and I. Tarantino contributed equally to this manuscript.